GLOSSARY OF TERMS

Airport planning and the Environmental Impact Statement (EIS) process require
the use of many technical terms. Some of the most important are defined in this
section. Terms in bold italics are defined separately in this glossary.

Air Carrier Aircraft -
Generally, U.S. registered large (12,500 pounds or more, by FAA definition)
transport category civil aircraft (excluding single-engine) of designated class
and type, that support scheduled passenger-carrying and cargo operations in air
commerce, pursuant to a Federal Aviation Administration air
carrier certificate issued under 14 CFR Parts 119 and 121 of the Federal
Aviation Regulations, (see 14 CFR 119.3, for Domestic, Flag,
and Supplemental definitions).

Air Route Traffic Control Center (ARTCC or Center) - A
Federal Aviation Administration facility established to provide air traffic control service to aircraft operating on Instrument
Flight Rules flight plans within controlled airspace,
principally during the en route phase of flight.
When equipment capabilities and controller workload permit, certain
advisory and assistance services may be provided to Visual Flight Rules
aircraft.

Air Taxi Aircraft - A
term no longer used by the Federal Aviation Administration, though
still used by the U.S. Department of Transportation (USDOT).The Federal Aviation
Administration uses the term "on demand" to describe those operations
formerly described as "air taxi."

Air Traffic -
Aircraft operating in the air or on an airport surface, exclusive of loading
ramps and parking areas.

Air Traffic Control (ATC) -An
FAA service operated for the public, to ensure adequate separation of aircraft
and to promote the safe, orderly, and expeditious flow of air traffic. The air
traffic facility with jurisdiction over mapped and designated airspace may
authorize aircraft to proceed under specified traffic conditions within
controlled airspace.

Airport Traffic Control Tower (ATCT) - An
air traffic control facility established on an airport to provide
for safe, orderly, and expeditious flow of air traffic arriving at and departing
from an airport, including airport surface areas such as runways and taxiways.

Air Traffic Service (ATS) Routes -
"ATS route," a generic term, includes "VOR Federal airways," "colored Federal
airways," "alternate airways," "jet routes," "Military Training Routes," "named
routes," and "RNAV routes."The
term "ATS route" serves as an overall title for listing the types of routes that
comprise the United States route structure.

Aircraft Approach Category - A
grouping of aircraft based on a speed calculation that takes into account the
stall speed in the landing configuration at maximum gross landing weight.An aircraft must fit only one
category; its category determines speed minimums that must be observed for
various maneuvers.For example, an
aircraft which falls in Category A, but is circling to land at a speed in
excess of 91 knots, must use the approach Category B minimums when
circling to land. The categories are:Category A - Speed less than 91 knots; Category B -Speed 91
knots or more but less than 121 knots; Category C - Speed 121 knots or
more but less than 141 knots; Category D - Speed 141 knots or more but
less than 166 knots; Category E- Speed 166 knots or more.(See 14 CFR Part 97.)

Aircraft Classes -For the
purposes of wake turbulence aircraft separation minimums, ATC classifies
aircraft as (a) Heavy - Aircraft capable of takeoff weights of more than
255,000 pounds whether or not they are operating at this weight during a
particular phase of flight, (b) Large - Aircraft of more than 41,000
pounds, maximum certificated takeoff weight, up to 255,000 pounds, or (c)
Small - Aircraft of 41,000 pounds or less maximum certificated takeoff
weight.

Aircraft Rescue and Fire-Fighting (ARFF) -The
department at an airport dedicated to protecting life and property, controlling
fire hazards, and performing general duties related to airport operations and
aircraft safety.

Airman's Information Manual (AIM) - A
publication containing basic flight information and air traffic control
procedures, designed primarily as a pilot's information and
instructional manual for use in the National Airspace System.

Airport Arrival Rate (AAR) - A
dynamic input parameter specifying the number of arriving aircraft which an
airport or airspace can accept from the Air Route Traffic Control Center
per hour.The AAR is used
to calculate the desired interval between successive arrival aircraft.

Airport Departure Rate - A
dynamic parameter specifying the number of aircraft per hour that can depart
from an airport and be accepted into the airspace.

Airport Improvement Program (AIP) - A
Federal funding program for airport improvements. AIP is periodically
reauthorized by Congress with funding appropriated from the Aviation Trust Fund.Proceeds to the Aviation Trust Fund
are derived from excise taxes on airline tickets, aviation fuel, etc.

Airport Layout Plan (ALP) - A
scaled drawing of existing and proposed land and facilities necessary for the
operation and development of the airport.The ALP shows boundaries and proposed additions to all areas owned or
controlled by the airport operator for airport purposes, the location and nature
of existing and proposed action, and the location on the airport of existing and
proposed non-aviation areas and improvements thereon.

Airport Operations - The
total takeoffs (departures) and landings (arrivals) from an airport.

Airport Reference Code (ARC) - A
coding system used to relate airport design criteria to the operational and
physical characteristics of the design aircraft intended to
operate at the airport (i.e. the most critical aircraft type currently using, or
projected to use, an airport, with a minimum of 500 operations per year). ARC
can either be one aircraft or a group of aircraft.The first component of the ARC is a
capital letter (A, B, C, D, or E with "A" being the lowest, and "E" being the
highest), which refers to the aircraft approach speed in its landing
configuration. The second component, which is depicted by a Roman numeral (I,
II, III, IV, V, VI, with "I" being the lowest and "VI" being the highest),
refers to aircraft wingspan. Together, the two components relate aircraft
operational and physical characteristics to the required design criteria of
various airport components, such as runway/taxiway widths, runway to taxiway
separation standards, and obstacle clearance items.Under this methodology, safety
margins are provided in the physical design of airport facilities.

Airport Surveillance Radar (ASR) -
Approach control radar used by air traffic controllers to detect and display an
aircraft's position in the airport terminal area. ASR provides range (distance)
and azimuth (direction) information with regard to arriving or
departing aircraft.

Air Traffic Service (ATS) Routes -
"ATS route," a generic term, includes "VOR Federal airways," "colored Federal
airways," "alternate airways," "jet routes," "Military Training Routes," "named
routes," and "RNAV routes."The
term "ATS route" serves as an overall title for listing the types of routes that
comprise the United States route structure.

Airway - A
corridor of controlled airspace whose centerline is established by
radio navigational aids. Low altitude airways (between 3,000 and
18,000 feet Mean Sea Level) are identified by number with the letter V as
a prefix.High altitude airways
(above 18,000 feet Mean Sea Level) are known as Jet airways and are
identified by number with the letter J as a prefix.

Ambient Noise - The
total sum of noise from all sources in a given place and time. This is also
known as Existing Ambient Noise. See also Natural
Ambient Noise.

Annual Service Volume (ASV) - A
reasonable estimate of an airport's annual capacity.It accounts for differences in
runway use, aircraft mix, weather conditions, etc, that would be encountered
over a year's time.

Approach Light Systems (ALS) - One
of various lighting aids that may be installed on an airport. The ALS is a
series of lights that provide visual guidance to landing aircraft by radiating
light beams in a directional pattern, to assist the pilot when aligning aircraft
with the extended runway centerline on final approach.

Area Navigation (RNAV) -A
method of navigational procedures designed to transition aircraft between an
airport environment and the en route system of airspace.RNAV procedures offer the advantages
of routings that save time and fuel, reduce dependence on radar vectoring,
altitude, and speed assignments, which allows for reduction in required radio
transmissions with Air Traffic Control, and more efficient use of
airspace.

Attenuation -
Acoustical phenomenon whereby sound energy is reduced between the
noise source and the receiver.This
energy loss can be attributed to atmospheric conditions, terrain, vegetation,
other natural features, and man-made features (e.g., sound insulation).

A-Weighted Sound (dBA) - A
system for measuring sound energy that is designed to represent
the response of the human ear to sound.Energy at frequencies more readily detected by the human ear is more
heavily weighted in the measurement, while frequencies less well detected are
assigned lower weights. A-weighted sound measurements are commonly used
in studies where the human response to sound is the object of the
analysis.

Azimuth - An
arc of the horizon measured between a fixed point (such as true north) and the
vertical circle passing through the center of an object.

Base Flight Segment - A
flight path at right angles to the landing runway off its approach end.The base segment normally extends
from the downwind segment to the intersection of the extended runway centerline.

Base Leg - A
flight path at right angles to the approach of a runway end.It usually extends from the downwind
leg to the intersection of the extended runway centerline.

Baseline Condition - The
existing condition or conditions prior to future development, which serve as a
foundation for analysis.

Building Restriction Line (BRL) -A
line drawn on an airport layout plan that distinguishes between
areas that are suitable for buildings and areas that are unsuitable.Typically, a 35-foot building height
is used to ensure that all the surfaces in 14 CFR Part 77 are clear.

Commuter Aircraft -
Generally, aircraft of designated size or seating capacity (usually nine or
fewer seats) that support scheduled air transportation services for compensation
or hire in air commerce, with a frequency of at least five round trip operations
per week on at least one route according to a published flight schedule.
Commuter aircraft operate pursuant to a Federal Aviation Administration
air carrier certificate issued under 14 CFR Parts 119 and 135 of the
Federal Aviation Regulations. (See 14 CFR 119.3, Definitions.)
Regional Jets (RJs) are not "commuters," because they are large
transport category aircraft and fall within the Federal Aviation
Administration's air carrier aircraft category.

Contour -See
Noise Contour.

Controlled Airspace - An
airspace of defined dimensions within which air traffic control
service is provided to flights operating under both Instrument Flight
Rules and Visual Flight Rules in accordance with the
airspace classification. Controlled airspace designated as Class A, Class
B, Class C, Class D, and Class E, generally
according to altitude above the surface, distance from a primary airport, and
volume of aircraft operations.
Controlled airspace is also that airspace within which all aircraft operators
are subject to certain pilot qualifications, operating rules, and equipment
requirements (for specific operating requirements, see 14 CFR Part 91).

Crosswind Leg - A
flight path at right angles to the approach runway end off of the upwind end.

Day-Night Average Sound Level (DNL) - A
noise measure used to describe the average sound level over a
24-hour period, typically an average day over the course of a year.In computing DNL, an extra weight of
ten decibels is assigned to noise occurring between the hours of
10:00 p.m. and 7:00 a.m. to account for increased annoyance when ambient noise
levels are lower and people are trying to sleep. DNL may be determined for
individual locations or expressed in noise contours.

dBA -See A-weighted Sound Level

Decibel (dB) -Sound
is energy and is measured by its pressure.Because of the enormous range of
sound pressures to which the human ear is sensitive, the raw sound pressure
measurement is converted to the decibel scale for purposes of
description and analysis. The decibel scale is logarithmic.A ten-decibel increase in
sound is perceived as a doubling of sound (or twice as loud) by the human
ear.

Departure Fix - A
departure fix, or so-called departure gate, is a section of airspace used to
separate departing from arriving aircraft.This fix determines the initial flight path and direction of the
aircraft.

Design Aircraft - The
most critical aircraft type currently using, or projected to use, an airport,
with a minimum of 500 operations per year.It can either be one aircraft or a group of aircraft. See also Airport Reference Code.

Detailed Study Area - One of
the areas identified for detailed environmental investigation as part of this Environmental Impact Statement. This study area is smaller in
scale than the General Study Area to accommodate the more detailed
analyses. (See General Study Area.)

Displaced Threshold - A
threshold that is located at a point on the runway other than the designated
beginning of the runway.The
portion of pavement behind a displaced threshold may be available for takeoffs
in both directions and landings from the opposite direction.

Distance Measuring Equipment (DME) -A
flight instrument that measures the line-of-sight distance of an aircraft from a
navigational radio station in nautical miles.

Double-Clear Zone - An
area on the ground, up to 1,250 feet from each side of the runway centerline and
extending 5,000 feet beyond each end of the primary runway surface.It is also known as the Approach
Transitional Area for runways serving or anticipated to serve turbojet
aircraft or having an existing or planned runway with an instrument
approach.

Downwind Approach/Arrival - A
flight path parallel to the landing runway in the direction opposite to landing.

Easement - The
legal right of one party to use part of the rights of a piece of real estate
belonging to another party.This
may include, but is not limited to, the right of passage over, on or below the
property; certain air rights above the property, including view rights; and the
rights to any specified form of development or activity.

Engine Run-ups - A
routine procedure for testing aircraft systems by running one or more engines at
a high power setting.Engine
run-ups are normally conducted by airline maintenance personnel checking an
engine or other on board systems following maintenance.

Enplanements - The
number of revenue passengers boarding an aircraft at an airport.

EnRoute Air Traffic Control System -
Unlike airport traffic control tower or terminal radar approach
control service, Air Route Traffic Control Centers provide enroute
service, generally for aircraft on Instrument Flight Rules
flight plans, when these aircraft are operating between departure and
destination airports at designated higher altitudes.When equipment, capabilities, and
controller workload permit, certain advisory/assistance services may be provided
to Visual Flight Rules aircraft.Enroute airspace is that airspace not delegated to approach control.

Environmental Impact Statement (EIS) - As
stated in CEQ regulation 40 CFR 1508.11, a detailed written statement that
complies with NEPA section 102 (42 USC 4332) by including in every report on
proposals for major Federal actions significantly affecting the quality of the
human environment, a detailed statement on (i) environmental impact of the
proposed action, (ii) any adverse environmental effects which cannot be avoided
should the proposal be implemented, (iii) alternatives to the proposal, (iv)
relationship between local short-term uses of the environment and maintenance
and enhancement of long-term productivity, and (v) any irreversible and
irretrievable commitment of resources involved in the proposed action, should it
be implemented.

Equivalent Sound Level (Leq) - The
A-weighted energy average sound level experienced
over a given period of time.The
metric is expressed as ten times the log of the total noise energy divided by
the number of seconds during the period under consideration.

Federal Aviation Administration (FAA) - The
FAA is the Federal agency responsible for insuring the safe and efficient use of
the nation's airspace, for fostering civil aeronautics and air commerce, and for
supporting the requirements of national defense.The activities required to carry out these responsibilities include:
safety regulations, airspace management and the establishment, operation and
maintenance of a system of air traffic control and navigation
facilities; research and development in support of the fostering of a national
system of airports, promulgation of standards and specifications for civil
airports, and administration of Federal grants-in-aid for developing public
airports; various joint and cooperative activities with the Department of
Defense, and technical assistance (under State Department auspices) to other
countries.

Federal Aviation Regulations (FAR) - The
body of Federal regulations enacted by the U.S. Secretary of Transportation,
under the statutory authority of the Federal Aviation Act and published in Title
14 of the Code of Federal Regulations (CFR).

Final Approach - A
flight path in the direction of landing that follows the extended runway
centerline.It usually extends from
the base leg to the runway.

Finding of No Significant Impact (FONSI) - As
stated in CEQ regulation 40 CFR 1508.13, a statement by a Federal agency
briefly describing why an action will not have a significant effect on the human
environment, supported by an environmental assessment or other appropriate
document.

Fix - An
imaginary point in the airspace, which describes a geographical position
determined through (i) visual reference to the surface, (ii) reference to one or
more radio navigational aids, (iii) celestial plotting, or (iv)
another navigational device.

Fixed-Base Operator (FBO) - A
business located on the airport that provides services such as hangar space,
fuel, flight training, repair, and maintenance to airport users.

Fleet Mix - The
mix or differing types of aircraft operating in a particular airport
environment.

Flight Track Utilization - The
use of established routes for arrival and departure by aircraft to and from the
runways at the airport.

FMS/GPS -
Flight Management System/Global Positioning System equipment
onboard an aircraft takes advantage of various radio navigation and/or Global
Positioning System routes to guide the aircraft.

General Aviation Aircraft -
Generally, those U.S. registered civil aircraft which operate for private and
noncommercial purposes and whose operations are not governed by 14 CFR Parts
119, 121, 125, or 135 of the Federal Aviation Regulations. General
aviation aircraft range from small single-engine propeller aircraft to large turbojet private aircraft.

Glide Slope (GS) -
Provides vertical guidance for aircraft during approach and landing. The glide
slope consists of the following:

Electronic components emitting signals which provide vertical guidance by
reference to airborne instruments during instrument approaches such as
Instrument Landing System, or visual ground aids, such as Visual
Approach Slope Indicator, which provide vertical guidance for
visual flight rules approach or for the visual portion of an
instrument approach and landing.

Geographic Information Systems (GIS) - An
information system that is designed for storing, integrating, manipulating,
analyzing, and displaying data referenced by spatial or geographic coordinates.

General Study Area -One of
the areas identified for environmental investigation as part of this EIS.
This study area is larger in scale than the Detailed Study Area. (See
Detailed Study Area.)

Global Positioning System (GPS) - A
system of 24 satellites used as reference points to enable navigators equipped
with GPS receivers to determine their latitude, longitude, and altitude.

Grid Analysis - A
type of aircraft noise analysis that evaluates the noise levels at individual
points rather than through generation of noise contours.

Ground Effect -
Noise attenuation attributed to absorption or reflection of noise
by man-made or natural features on the ground surface.

Hub - An
airport that services airlines that have hubbing operations.

Hubbing - A
method of airline scheduling that times the arrival and departure of several
aircraft in a close period of time in order to allow the transfer of passengers
between different flights of the same airline in order to reach their ultimate
destination.Several airlines may
conduct hubbing operations at an airport.

Infill -Urban
development occurring on vacant lots in substantially developed areas; may also
include the redevelopment of areas to a greater density.

Instrument Approach -A
series of predetermined maneuvers for the orderly transfer of an aircraft under
instrument flight rules from the beginning of the initial approach
to a landing, or to a point from which a landing may be made visually.

Instrument Flight Rules (IFR) -
That portion of the Federal Aviation Regulations (14 CFR Part 91)
specifying the procedures to be used by aircraft during flight in
Instrument Meteorological Conditions. These procedures may also be used
under visual conditions and provide for positive control by
Air Traffic Control. (See also Visual Flight Rules).

Instrument Landing System (ILS) -An
electronic system installed at some airports which helps to guide pilots to
runways for landing during periods of limited visibility or adverse weather.

Instrument Meteorological Conditions (IMC) -
Weather conditions expressed in terms of visibility, distance from clouds, and
cloud ceilings during which all aircraft are required to operate using
Instrument Flight Rules (IFR).

Itinerant Operation -An
aircraft flight that ends at an airport different from where the flight began.

Knots
-Airspeed measured as the distance in nautical miles (6,076.1
feet) covered in one hour. (Approximately equal to 1.15 miles per hour.)

Land Use Compatibility - The
ability of land uses surrounding the airport to coexist with airport-related
activities with minimum conflict.

Landing and Takeoff (LTO) Cycle - The
time that an aircraft is in operation at or near an airport. An LTO cycle begins
when an aircraft starts its final approach (arrival) and ends
after the aircraft has made its climb-out (departure).

Ldn -See
DNL. Ldn is used in place of DNL in mathematical equations
only.

Leq -See
Equivalent Sound Level.

Local Operation - An
aircraft flight that begins and ends at the same airport.

Localizer - The
component of an Instrument Landing System that provides lateral
course guidance to the runway.

Mean Sea Level (MSL) - The
average height of the surface of the sea for all stages of the tide; used as a
reference for elevations; also called sea level datum.

Medium Intensity Approach Lighting System with Runway Alignment Indicator Lights
(MALSR) -A
lighting system installed at some airports that pilots use during
instrument approaches to align the aircraft with the centerline of the
runway.Steady-burning white lights
are used to create a reference plane and white strobe lights create a sequential
flash pattern that rolls toward the runway threshold, which is
marked by steady-burning green lights.Varying intensity settings allow the approach to be used under changing
weather conditions.

Military Operations Area -
Airspace established to separate or segregate certain non-hazardous military
activities from Instrument Flight Rules traffic and to identify
for Visual Flight Rules traffic where these activities are
conducted.

Missed Approach - A
maneuver conducted by a pilot when an instrument approach cannot
be completed for landing at an airport.Instrument approach procedure charts show the route of flight and
altitude that the pilot must follow in this circumstance.

National Airspace System (NAS) - The
common network of U.S. airspace, air navigation facilities, equipment, services,
airports, or landing areas; aeronautical charts, information, and services;
rules, regulations, and procedures; technical information, manpower, and
materials, all of which are used in aerial navigation to provide a safe and
efficient flying environment.

National Environmental Policy Act of 1969 (NEPA) - The
original legislation establishing the environmental review process for proposed
Federal actions.

Nautical Mile - A
measure of distance equal to one minute of arc on the earth's surface (6,076.1
feet or 1,852 meters).

NAVAIDs (Navigational Aids) - Any
facility used by an aircraft for navigation.

Navigational Fix - A
geographical position determined by reference to one or more radio navigational
aids.

Noise Abatement - A
measure or action that minimizes the amount of impact of noise on the environs
of an airport.Noise abatement
measures include aircraft operating procedures and use or disuse of certain
runways or flight tracks.

Nondirectional Beacon (NDB) - A
beacon transmitting non-directional signals whereby the pilot of an aircraft
equipped with direction finding equipment can determine the bearing to and from
the station.When the radio beacon
is installed in conjunction with the Instrument Landing System
marker, it is normally called a compass locator.

On-Demand -Generally,
U.S. registered civil aircraft of designated size (usually 30 or fewer passenger
seats with payload capacity of 7,500 pounds or less) that support on-demand,
unscheduled, or infrequently scheduled passenger-carrying or cargo service
(including public charters) for compensation or hire, pursuant to a air carrier
certificate issued under 14 CFR Parts 119 and 135 of the Federal Aviation
Regulations.(See 14 CFR
119.3, Definitions.)This term
includes operations formerly classified as air taxi, a term no longer used by
the Federal Aviation Administration but still used by the U.S.
Department of Transportation (USDOT).

Outer Fix - An
air traffic control term for a point in the airspace from which
aircraft are normally cleared to the approach fix or final approach course.

Outer Marker (OM) - An
Instrument Landing System navigation facility in the terminal area
navigation system located four to seven miles from the runway edge on the
extended centerline indicating to the pilot that he/she is passing over the
facility and can begin final approach.

Positive Control - The
separation of all air traffic within designated airspace as directed by
air traffic controllers.

Precision Approach Path Indicator (PAPI)
-Provides visual approach slope guidance to aircraft during an approach.It is similar to a Visual
Approach Slope Indicator but provides a sharper transition between the
colored indicator lights.

Precision Approach Radar (PAR) -
Navigational equipment located on the ground adjacent to the runway, consisting
of one antenna, which scans the vertical plane, and a second antenna, which
scans the horizontal plane.The PAR
provides the controller with a picture of the descending aircraft in
azimuth, distance, and elevation, permitting an accurate determination
of the aircraft's alignment relative to the runway centerline and the
glide slope.

Profile - The
position of the aircraft during an approach or departure in terms of altitude
above the runway and distance from the runway end.

Propagation -Sound
propagation is the spreading or radiating of sound energy from the noise
source. It usually involves a reduction in sound energy with increased distance
from the source.Atmospheric
conditions, terrain, natural objects, and manmade objects affect sound
propagation.

Public Use Airport - An
airport open to public use without prior permission, and without restrictions
within the physical capabilities of the facility.It may or may not be publicly-owned.

Regional Jet - A
jet aircraft that falls within the air carrier aircraft category because of size
and payload.For use in air
commerce, the regional jet must be operated pursuant to an air
carrier certificate pursuant to an air carrier certificate issued under 14 CFR
Parts 119 and 121 of the Federal Aviation Regulations. (See
14 CFR 119.3, for Domestic, Flag, and Supplemental operations). Regional
jets are not operated as commuter aircraft pursuant to 14 CFR Part 135.Regional jets are typically
jet aircraft, with approximately 35 to 90 seats.The next-generation regional jets are expected to seat 100
passengers.

Reliever Airport -An
airport which, when certain criteria are met, relieves the aeronautical demand
on a busier air carrier airport.

Retrofitted Aircraft - An
aircraft originally certified as Stage 2 that has been modified to
meet Stage 3 requirements.This includes both modification of engines or the replacement of engines
to meet the Stage 3 standard.

RNAV -See
Area Navigation.

Run-up - A
routine procedure for testing aircraft systems by running one or more engines at
a high power setting.Engine
run-ups are normally conducted by airline maintenance personnel checking
an engine or other on board systems following maintenance.

Runway End Identifier Lights (REIL) - Two
synchronized flashing lights, one on each side of the runway threshold,
which identify the approach end of the runway.

Runway Protection Zone (RPZ) - An
area, trapezoidal in shape and centered about the extended runway centerline,
designated to enhance the protection of people and property on the ground.It begins 200 feet (60 M) beyond the
end of the area usable for takeoff or landing.The RPZ dimensions are functions of the aircraft, type of operation, and
visibility minimums.(Formerly
known as the clear zone.)

Runway Safety Area (RSA) - A
defined surface surrounding the runway prepared or suitable for reducing the
risk or damage to airplanes in the event of an undershoot, overshoot, or
excursion from the runway.

Runway Threshold - The
beginning of that portion of the runway usable for landing.

Scoping -Scoping
is an early and open process for determining the scope or range of issues to be
addressed in the Environmental Impact Statement and identifying
the significant issues related to a proposed action.Issues important to the public and
local, state, and Federal agencies are solicited through direct mailing, public
notices, or meetings.Scoping is
generally conducted before development of the Environmental Impact
Statement scope of work.

Single event -One
noise event.For many kinds of
analysis, the sound from single events is expressed using the Sound Exposure Level metric.

Slant-range distance - The
distance along a straight line between an aircraft and a point on the ground.

Sound
-Sound is the result of vibration in the air.The vibration produces alternating bands of relatively dense and sparse
particles of air, spreading outward from the source in the same way as ripples
do on water after a stone is thrown into it. The result of the movement is
fluctuation in the normal atmospheric pressure or sound waves.

Sound Exposure Level (SEL) - A
standardized measure of a single (sound) event, expressed in A-weighted decibels, that takes into account all sound above a
specified threshold set at least ten decibels below the maximum
level.All sound energy in the
event is integrated over one second.

Special Use Airspace -
Airspace of defined dimensions identified by an area on the earth's surface
wherein activities must be confined because of their nature and/or wherein
limitations may be imposed upon aircraft operations, which are not
part of those activities.

Stage 2 Aircraft -
Aircraft that meet the noise levels prescribed by Federal Aviation
Regulations 14 CFR Part 36, which are less stringent than those
established for the quieter Stage 3 designation. The Airport Noise
and Capacity Act required the phase-out of all Stage 2 aircraft over 75,000
pounds by December 31, 1999, with the potential for case-by-case exceptions
through the year 2003.

Standard Instrument Departure Procedure (SID) - A
planned Instrument Flight Rules air traffic control departure
procedure published for pilot use in graphic and textual form.SIDs provide transition from the
terminal to the en route air traffic control structure.

Standard Terminal Arrival Route (STAR) - A
planned Instrument Flight Rules air traffic control arrival
procedure published for pilot use in graphic and textual form. STARs provide
transition from the en route air traffic control structure to an
outer fix or an instrument approach fix in the
terminal area.

Statute Mile - A
measure of distance equal to 5,280 feet.

TACAN -
Tactical Air Navigation.A
navigational system used by the military. TACAN provides both azimuth and distance information to a receiver on board an aircraft.

Terminal Radar Approach Control (TRACON) -A Federal Aviation Administration Air Traffic Control Facility which
uses radar and two-way communication to provide separation of air traffic within
a specified geographic area in the vicinity of one or more airports.

Terminal Radar Service Area (TRSA) -
Airspace surrounding certain airports where Air Traffic Control
provides radar vectoring, sequencing, and separation on a
full-time basis for all Instrument Flight Rules and participating
Visual Flight Rules aircraft.

Time Above (TA) - The
amount of time that sound exceeds a given decibel
level during a 24-hour period (e.g., time in minutes that the sound level is
above 75 decibels).

Thrust Settings -
Settings on an aircraft that control the power applied to the engines.

Turbojet - An
aircraft powered by a jet turbine engine.The term is customarily used in air traffic control for all
aircraft, without propellers, that are powered by variants of jet engines,
including turbofans.

Turboprop -
Aircraft of this type are typically used by airlines on short routes between two
relatively close locations.

UNICOM - A
nongovernment communication facility that may provide information to pilots on
UNICOM frequencies at certain towers, generally, those without operating
airport traffic control towers, or those closed at certain periods of
day or night.Aeronautical charts
and publications show UNICOM frequencies and locations.

Upwind Leg - A
flight path parallel to the approach runway in the direction of approach.

Vector -
Compass heading instructions issued by Air Traffic Control in
providing navigational guidance by radar.

Very High Frequency Omnidirectional Range (VOR) Station - A
ground-based radio navigation aid transmitting signals in all directions.A VOR provides azimuth guidance to pilots by reception of electronic signals.

Very High Frequency Omnidirectional Range Station with Tactical Air Navigation
(VORTAC) - A
navigational aid providing VOR azimuth and Tactical Air
Navigation distance measuring equipment at one site.

Visual Approach - An
approach conducted on an Instrument Flight Rules flight plan,
which authorizes the pilot to proceed visually and clear of clouds to the
airport.

Visual Approach Slope Indicator (VASI) - A
visual aid for final approach to the runway threshold, consisting
of two wing bars of lights on either side of the runway. Each bar produces a
split beam of light - the upper segment is white, the lower is red.

Visual Flight Rules (VFR) -
Rules and procedures specified in Federal Aviation Regulations 14
CFR Part 91 for aircraft operations under visual conditions. Aircraft operations
under VFR are not generally under positive control by Air
Traffic Control. The term VFR is also used in the U.S. to indicate
weather conditions that are equal to or greater than minimum VFR requirements.
In addition, it is used by pilots and controllers to indicate a type of flight
plan.

Visual Meteorological Conditions (VMC) -
Weather conditions expressed in terms of visibility, distance from cloud, and
cloud ceiling equal to or greater than those specified in Federal Aviation
Regulations 14 CFR Part 91.155
for aircraft operations under Visual Flight Rules.